Charles Bean: 'There’s a case for moving gradually because we won’t be quite certain about the impact of tightening the bank rate given everything that has happened.' Photograph: Graham Barclay/Getty Images

UK interest rates could start rising before next spring – but "in baby steps" – and are likely to settle at about 3% in a few years' time, the Bank of England's outgoing deputy governor has predicted.

It will take three to five years for borrowing costs to rise to about 3%, Charles Bean said, but below the average of 5% seen in the decade before the financial crisis. The main UK interest rate has been held at 0.5%, a historic low, since March 2009, and the central bank's governor, Mark Carney, has indicated that rates will not rise until next year.

Financial markets have priced in a rate rise in March or April 2015, although a move seems more likely in an inflation report month – February or May – when the Bank can use its latest economic forecasts to explain the rationale for an increase.

He said: "There's a case for moving gradually because we won't be quite certain about the impact of tightening the bank rate given everything that has happened to the economy.

"It might not operate in quite the same way as it did before the crisis. So that's an argument if you like for being a little bit cautious, moving in baby steps to avoid making mistakes. If you want to pursue that strategy you need to start taking those baby steps a bit earlier, otherwise you end up being behind the curve."

His view is shared by some other members on the monetary policy committee, who are arguing that raising rates sooner would lead to a gentler upward slope.

Bean stressed there was no need to raise rates straight away, saying: "One of the risks about moving too early is that you potentially forgo some [economic] activity that you might otherwise have had and one of the key issues for us will be whether we see some recovery in productivity which has been unusually subdued in recent years, and maybe if we nip the recovery too early then we won't see that productivity rebound."

Interest rates were cut to a record low during the global financial crisis. Rising house prices in parts of the UK and other evidence that the economy is recovering strongly have fuelled a debate about when interest rates will go up.

Bean said the lingering economic impact of the financial crisis would mean rates would stay lower than before the credit crunch, settling at about 3% in the next few years.

Bean told the BBC: "The Bank rate averaged about 5% in the decade or so before the crisis. It's reasonable to think that because of the headwinds that are still out there as well as some the global forces that perhaps the level that we go to three or five years out might be a couple of percentage points below that."

He flagged up geopolitical risks to the economy including the Ukraine crisis, China's shadow banking system and the possibility of the US Federal Reserve returning to "normal" monetary policy earlier than expected.

Asked about the UK housing market, Bean said authorities were more worried about rising household debt than house prices per se, and the Bank's financial policy committee could step in.

"Where the issues really start potentially being worrying is the accumulation of debt. So if there's signs that banks are making loans to borrowers who may not be able to repay or we have doubts about ... whether those households will be able to keep their consumption up if they borrow a lot, then they are reasons why the Bank's financial policy committee might want to take some action to rein things back a bit."

Bean said both were "extremely serious charges", echoing comments made by Carney in March. "Any attempt to manipulate markets – whether it's the interbank market through manipulating Libor, the foreign exchange market through trying to manipulate the fix there – for private gain strikes at the integrity of markets.

"Markets can't function properly if people can't trust the actors involved as intermediaries to ensure they behave in an appropriate fashion."

He added: "It certainly speaks to the need to be continually vigilant … We need to be much more conscious of the scope for misbehaviour as well as complacent behaviour."